i'm confused a little, however i think your map system isn't ideal. here you might find a simpler way...
Data(0,offset_to_room2_data,offset_to_room3_data,etc)->GDB1
[<all map data strewn together>]->GDB2

then say your variable for the current level is L. to display it you'd just start reading from GDB2+{GDB1+L}.
if you need to have GDB1 contain sizes of the map, this can be modified to work.
if your current level is N, just make sure you get the sum of {GDB+[1..N-1]}, and start reading from that + GDB2

yes. BrandonW explained it's probably for people in the factories at singapore. the only difference between it and a normal ram clear is that language options aren't reset when you get one from singapore.

i'd bump it down a few, to like 16-20.

i was messing around with the program below, and out popped this picture. it looked kinda cool, so i thought i'd post it here. best part? the tracks are 8 pixels tall (:

ClrDraw
[FFFFFFFFFFFFFFFF]->Pic1
0->D->F
Repeat getKey(15)
If F:D+1->D
Else:D-1->D:End
If D=0 or (D=-88)
F xor 1->F:End
C+4->C
Pt-Change(88+D,sin(C)//6+30,Pic1
DispGraph
End

edit: will upload a PNG of it soon

if you're looking for the AP Computer Science one, i can definitely copy/paste you some questions my teacher gives as samples.

this is still difficult to grasp. does this description summarize what you want?
a string of bytes which each correspond to a sprite.
there is another string of bytes corresponding with the first string of bytes. this string says "after X pixels scrolled, draw the object on the screen"
there is a third string telling the routine where to place the sprite.
for example, considering 1 is a meteor sprite and 2 is a tree sprite:
Data(1,2)->Str1     // what object 1 = meteor, 2 = tree
Data(50,30)->Str2 // every 50 pixels scrolled, display a meteor. every 30 pixels scrolled, display a tree.
Data(0,45)->Str3 // when you display a meteor, display it at (88,0). when you display a tree, display it at (88,45)

am i right?
if so, here's some code assuming the above declarations:
[meteor_sprite_hex]->Pic1
[tree_sprite_hex]
Repeat getKey(15)
   ...
   For(Z,0,length(Str1)-1
      !If pixelsScrolled^{Str2+Z}
         Pt-Off(88,{Str3+Z},{Str1+Z}-1*8+Pic1
      End
   End
   ...
End

edit: and runer, i know it can be heavily optimized. but i just tried to make an example obvious to what i am doing

is that shorter than just using a loop though? it's probably faster granted

so you want to get the number of digits in the fractional part of a number, am i right?